Safety plug muffler installation



Sept. 3, 1963 .1v B. WILHELMI SAFETY PLUG MUFFLER INSTALLATION Filed Sept. 18, 1961 Inven'imr: Julius B. Wilhelm. 33 M W 22:9

United States Patent 3,102,657 SAFETY PLUG MUFFLER INSTALLATION Julius B. Wilhelmi, Nantasket, Hull, Mass, assignor to United-Carr Fastener Corporation, Cambridge, Mass, a corporation of Delaware Filed Sept. 18, 1961, Ser. No. 138,967 4 Claims. (Cl. 220-245) This invention aims to provide an improved safety plug installation preferably in connection with mufllers of the exhaust systems of combustion motors such as used in motor vehicles and the like.

A preferred embodiment of the invention relates to a safety plug fastener of a type that may be used to close an aperture in a ceramic coated muffier, the plug fastener being of simple construction, easily tool applied and that will withstand at least nine hundred pounds of pressure after application.

Referring to the drawings:

FIG. 1 is a plan view of a portion of the installation as it appears from outside the mufiler;

FIG. 2 is a plan view of the installation as it appears from inside the muffler;

FIG. 3 is a section taken on the line 3-3 of FIG. 1;

FIG. 4 is a section similar to FIG. 3 showing arrangement of the parts of the safety plug fastener prior to complete assembly with the mufiler structure; and

FIG. 5 is an edge view including each of the two pieces of the plug fastener prior to assembly.

In the present day improved mufflers for exhaust systems of combustion motors, it is the practice to ceramically coat the mufflers inside and out in order to lengthen the life of the mufller. In most cases it is necessary to have two or more apertures, preferably one in each end of the mufller, so as to permit proper baking of the ceramic material applied to the muffler. It is, of course, necessary to close the apertures after completion of the ceramic baking operation; and heretofore it was found necessary to weld a plug into an aperture in order that it might be securely attached and hold against pressures built up in mufflers during operation of combustion motors. This has been a costly hole-closing operation and care had to be exercised in order not to damage the ceramic coating outside the hole closure.

The present invention contemplates the use of the safety plug fastener that is simple in construction, easy to apply; and tests have proved that it will remain in place up to nine hundred pounds pressure, which is about double the normal pressure in an ordinary mufiler.

The preferred form of installation illustrated by the FIGURE 3 shows another modification in which two parallel series of inner sluicing chambers are provided in drawings includes a portion of a muffler body 1 having an aperture therethrough surrounded by an upstanding wall 2 to strengthen the material around the aperture and pro vide a sizable bearing surface for the safety plug device. The ceramic coating is indicated by the numeral 3.

The safety plug fastener illustrated is formed of two pieces (FIG. 5) in the form of a ferrule member 4 and an expanding member 5 and which may be initially telescoped within each other to a position shown in FIG. 4. Then the assembled plug may be inserted into the aperture in the support, to the position shown in FIG. 4.

The ferrule member has a flange portion 6 which fits over the end of the upstanding wall 2 and has a sleeve portion 7 extending downwardly through the aperture in the support (FIG. 4) with an expandable portion 8 extending beyond the inner surface of the mufller body 1 and curled inwardly. This inwardly curled expandable portion 8 is divided by a suitable number of slits 9 so the expandable portion may be more easily expanded and 3,102,657 Patented Sept. 3, 1963 also so that it may grip and hold the expanding member 5 in the preassembly of the parts.

The expanding member 5 is in the form of a eupshaped member and has a wall portion 10 of a diameter to snugly fit the inturned expanding portion 8 of the ferrule member 4 (FIG. 4). It also has a wall portion 11 of increased diameter which may be forced into the expandable ferrule 4 thereby forcing the expandable portion 8 outwardly to tightly grip the body of the mufller as shown in FIG. 3. Another enlarged annular wall portion 12 is provided be yond the wall portion 11 to act as stop means to prevent movement of the expanding member through the ferrule.

Installation of the safety plug fastener may be accomplished in any suitable manner depending upon the accessibility from the inner side of an aperture support. However, in muffler constructions it is practically impossible to do any work on the safety plug fastener from the inside of the muffler. Therefore, the improved device is in the nature of a blind plug fastener which may be inserted from the outer exposed side of the muffier and the expanding member 5 may be moved axially relative to the ferrule 4 by a suitable tool (not shown). The tool may rest upon the flange 6 of the ferrule 4 and grip a tool operable portion 13. The tool may be so constructed that the portion thereof that grips the tool operable portion 13 may move relative to the portion that rests upon the flange 6 to cause the movement of the expanding member from the position shown in FIG. 4 to the position shown in FIG. 3 as will be readily understood by anyone skilled in the art.

It is believed that from the above description and the various figures comprising the drawings that anyone skilled in the art will appreciate that the device is inexpensive in construction, easily installable and the parts thereof are so arranged and formed that once the safety plug fastener is completely installed a seal is provided to prevent leakage through an aperture in the mufller. It will also be obvious that any pressure exerted upon the plug fastener from the inside of the muffler will tighten the application with no tendency to loosen the construction.

While there has been illustrated and described one preferred embodiment of the invention, it should be understood that the invention is best defined by the following claims.

I claim:

1. A safety plug installation for exhaust mufflers and the like comprising, a combination, an apertured housing structure and a blind plug fastener assembled in an aperture in said housing structure, said plug fastener including an expandable ferrule fitted into said aperture and having a portion expanded and securely attaching the ferrule to the housing structure and an expanding member assembled within said ferrule and having a ferrule expanding portion of enlarged diameter within the housing structure holding said ferrule in expanded position, a tool operable portion at one end of the expanding member and exposed at the outside of the housing structure and operated upon to move the expanding member axially relative to the expandable ferrule whereby the ferrule expanding portion is moved into expanding position and a stop means within the housing at the other end of the expanding member opposite the tool operable portion to limit movement of the expanding member.

2. A safety plug installation for exhaust mufflers and the like comprising, in combination, an apertured housing structure and a blind plug fastener assembled in an aperture in said housing structure, said plug fastener ineluding an expandable ferrule fitted into said aperture and having a flange engaging the housing structure adjacent to the aperture, a portion expanded and securely attaching the ferrule to the housing structure and a hollow impreforate Wall cup-shaped expanding member assembled within said ferrule and having a ferrule expanding portion of enlarged diameter within the housing structure holding said ferrule in expanded position, and a tool operable portion exposed at the outside of the housing structure and operated upon to move the expanding member axially relative to the expandable ferrule whereby the ferrule expanding portion is moved into expanding position.

3. A safety plug installation for exhaust mufllers and the like comprising, in combination, an apertured housing structure and a blind plug fastener assembled in an aperture in said housing structure, said plug fastener including an expandable ferrule fitted into said aperture and having a portion expanded and securely attaching the ferrule to the housing structure and a hollow expanding member assembled within said ferrule and having a ferrule expanding portion of enlarged diameter within the housing structure holding said ferrule in expanded position, a reduced portion fitting into the ferrule, said expandable ferrule having slits in the expanded portion and said expanding member being imperforate to the passage of air and cooperating with the ferrule to form a pressure tight plug.

4. A safety plug installation for exhaust mufilers and the like comprising, in combination, an apertured housing structure and a blind plug fastener assembled in an aperture in said housing structure, said plug fastener including an expandable ferrule fitted into said aperture and having a portion expanded and securely attaching the ferrule to the housing structure and a hollow expanding member assembled within said ferrule and having a ferrule expanding portion of enlarged diameter within the housing structure holding said ferrule in expanded position, a reduced portion fitting into the ferrule, said expandable ferrule having slits in the expanded portion and said expanding member being imperforate to the passage of air and cooperating with the ferrule to form a pressure tight plug, a projecting portion on said expanding member for engagement by a tool to move said expanding member into expanding engagement with said ferrule and an annular stop adjacent the enlarged portion to restrain movement of the expanding member.

Bohmer Mar. 12, 1957 Fuller Jan. 2, 1962 

1. A SAFETY PLUG INSTALLATION FOR EXHAUST MUFFLERS AND THE LIKE COMPRISING, A COMBINATION, AN APERTURED HOUSING STRUCTURE AND A BLIND PLUG FASTENER ASSEMBLED IN AN APERTURE IN SAID HOUSING STRUCTURE, SAID PLUG FASTENER INCLUDING AN EXPANDABLE FERRULE FITTED INTO SAID APERTURE AND HAVING A PORTION EXPANDED AND SECURELY ATTACHING THE FERRULE TO THE HOUSING STRUCTURE AND AN EXPANDING MEMBER ASSEMBLED WITHIN SAID FERRULE AND HAVING A FERRULE EXPANDING PORTION OF ENLARGED DIAMETER WITHIN THE HOUSING STRUCTURE HOLDING SAID FERRULE IN EXPANDED POSITION, A TOOL OPERABLE PORTION AT OEN END OF THE EXPANDING MEMBER AND EXPOSED AT THE OUTSIDE OF THE HOUSING STRUCTURE AND OPERATED UPON TO MOVE THE EXPANDING MEMBER AXIALLY RELATIVE TO THE EXPANDABLE FERRULE WHEREBY THE FERRULE EXPANDING PORTION IS MOVED INTO EXPANDING POSITION AND A STOP MEANS WITHIN THE HOUSING AT THE OTHER END OF THE EXPANDING MEMBER OPPOSITE THE TOOL OPERABLE PORTION TO LIMIT MOVEMENT OF THE EXPANDING MEMBER. 